class A(object):
    def __init__(self):
        print("A")


class B(A):
    def __init__(self):
        #A.__init__(self)
        super().__init__()
        print("B")


class C(A):
    def __init__(self):
        A.__init__(self)
        # super().__init__()
        print("C")


class D(B, C):
    def __init__(self):
        super(C,self).__init__()
        print("D")

d = D()
print(D.__mro__)
